iOS Encoding strings for well formed URL's

[nashyo]

There appears to be some distrust in the iOS SDK, specifically the NSString class method that escapes strings.

Using the following resource as guidance I have created a category class that is an extension of NSString.

http://madebymany.com/blog/url-encoding-an-nsstring-on-ios

.h

#import <Foundation/Foundation.h>

@interface NSString (URLEncoding)
-(NSString*)urlEncodingUsingEncoding:(NSStringEncoding)encoding;
@end

.m

@implementation NSString (URLEncoding)
-(NSString*)urlEncodingUsingEncoding:(NSStringEncoding)encoding
{
    return (__bridge NSString*)CFURLCreateStringByAddingPercentEscapes(NULL, (__bridge CFStringRef)self, NULL, (CFStringRef)@"!*'\"();;@&=+$,/?%#[]% ", CFStringConvertNSStringEncodingToEncoding(encoding));
}
@end

When I import this class and attempt to create an instance, I cannot call the class method 'alloc'. Why hasn't this been inherited?

Further, I have tried abandoning the use of this category class and simply calling some C functions as so:

NSString *escapedString = (__bridge NSString *)CFURLCreateStringByAddingPercentEscapes( NULL, (__bridge CFStringRef)grade,	 NULL,	 (CFStringRef)@"!’\"();:@&=+$,/?%#[]% ", kCFStringEncodingISOLatin1);

However, I'm getting issues with this also. The NSLog that follows this piece of code has a warning from Xcode (slightly above it actually in the empty space between) 'data argument not used by format string':

NSLog(@"Test", escapedString);

Such a simple task, yet so many errors. What am I doing wrong here?

 

[PhoneyDeveloper]

NSLog(@"Test: %@", escapedString);